Using the Python API

The Python libmxidaf library comes pre-installed in the ThingsPro Gateway. To use the library, just import it in your Python source file.

from libmxidaf_py import TagV2, Modbus

Initializing the Tag Library

To initialize the library, get an instance of TagV2.

To get TagV2 instance in Python, do the following:

tagv2 = TagV2.instance()

Publishing Tags

To publish Tags, use TagV2.publish().

from libmxidaf_py import Tag, Time, Value

tagv2.publish(
    "Equipment-name",
    "Tag-Name",
    Tag(
        Value(1.38),
        Time.now(),
        "Unit"
    )
)

Sample

A sample application is available at:

/usr/share/mxdaf/libmxidaf_py/sample/publish.py

Subscribing to Tags

To subcribe to Tags, use TagV2.subscribe() or TagV2.subscribe_callback() as follows:

tagv2.subscribe(
    "Subscribe_Equipment",
    "SubScribe_Tag");

def my_callback_func(equipment_name, tag_name, tag):
    # do something here
    pass

tagv2.subscribe_callback(my_callback_func)

Sample

A sample application is available at:

/usr/share/mxdaf/libmxidaf_py/sample/subscribe.py

Initializing the Modbus Library

To initialize the modbus library, create a Modbus instance.

To create Modbus instance in Python, do the following:

modbus = Modbus.instance();

Reading the Modbus Tags

To read Modbus Tags, use Modbus.read().

tag = modbus.read("Equipment-Name", "Tag-Name")

Sample

A sample application is available at:

/usr/share/mxdaf/libmxidaf_py/sample/modbus.py

Updating Modbus Tags

To write values to Modbus Tags, use Modbus.write().

from libmxidaf_py import Tag, Time, Value

modbus.write(
    "Equipment-Name",
    "Tag-Name",
    Tag(
        Value(1.38),
        Time.now(),
        "Unit"
    )
)

Sample

A sample application is available at:

/usr/share/mxdaf/libmxidaf_py/sample/modbus.py